Help on timing with a snap on mt1480

[Chumwon91]

Hello everyone, after years I finally managed to come across a timing light for the old diesels at an auction and was pumped to get it! Seems very complete and for $35 I'm more than happy and worth the risk that it still works. After studying the instructions I finally tried it yesterday on the ole 7.3 and it worked!

My questions about it though is
1. There's 2 holes in the timing ticker on the harmonic balancer. I used the taller one closer to the center of the motor. Is that the correct one?
2. What rpm do I check at? I did 2000 on my practice run but I've seen people say 1800 and 1400 aswell.
3. What number am I shooting for? I've seen .5-1.5 and I've also seen 5-7?

I know the luminosity isn't the most desired way but it's what I got to work with unfortunately. In my practice run at 2000rpm I got -.5 are negative numbers what I'm going for since it's atdc instead of btdc?

I do greatly appreciate any of your guys input. It's been years I've wanted to check the timing and am excited to do so! Thanks a ton in advance everyone!!

PS. I had to make a new account because I forgot my password an my email was being a pain!!!lol

 

[IDIBRONCO]

I'm pretty sure that the degree specs are different for the lumi method that the pulse/timing light method so I can't comment there. It's set at 2000RPM for the pulse method, but I don't know about the lumi method. Sorry I couldn't have been more help.

 

[BlindAmbition]

This thread has info that should help steer you in the right direction.

Using a Rotunda 78-0100 Tach & Time meter

-------------------------------------------------------------------------------- Anybody got one of these and know how to use it? I just bought one off fleabay for $99, and it looks like it hasn't been used more than a couple of times. Nearly brand new condition. There isn't even any grease...

www.oilburners.net

 

[Chumwon91]

Thank you much sir, that thread answered most everything. Now I'm guessing since I see nothing mentioning negative numbers that I'm looking for positive numbers.

 

[Chumwon91]

I stand corrected, it's definitely negative numbers. Didn't like 5 but it's at -6 and much better power up top. Might slightly tweak it down the road but I'll test performance and fuel economy for a while.